diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 1244693..d06a9df 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -25,6 +25,7 @@
 #include "qemu-common.h"
 #include "block/block_int.h"
 #include "block/qcow2.h"
+#include "qemu/range.h"
 
 static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size);
 static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs,
@@ -1372,3 +1373,150 @@ fail:
     return ret;
 }
 
+#define overlaps_with(ofs, sz) \
+    ranges_overlap(offset, size, \
+        (ofs) & ~(cluster_mask), \
+        ((sz) + ((ofs) & (cluster_mask)) + (cluster_mask)) & ~(cluster_mask))
+
+/*
+ * Checks if the given offset into the image file is actually free to use by
+ * looking for overlaps with important metadata sections (L1/L2 tables etc.),
+ * i.e. a sanity check without relying on the refcount tables.
+ *
+ * The chk parameter specifies exactly what checks to perform (being a bitmask
+ * of QCow2MetadataOverlap values).
+ *
+ * Returns:
+ * - 0 if writing to this offset will not affect the mentioned metadata
+ * - a positive QCow2MetadataOverlap value indicating one overlapping section
+ * - a negative value (-errno) indicating an error while performing a check,
+ *   e.g. when bdrv_read failed on QCOW2_OL_INACTIVE_L2
+ */
+int qcow2_check_metadata_overlap(BlockDriverState *bs, int chk, int64_t offset,
+                                 int64_t size)
+{
+    BDRVQcowState *s = bs->opaque;
+    int64_t cluster_mask = s->cluster_size - 1;
+    int i, j;
+
+    if (!size) {
+        return 0;
+    }
+
+    if (chk & QCOW2_OL_MAIN_HEADER) {
+        if (offset < s->cluster_size) {
+            return QCOW2_OL_MAIN_HEADER;
+        }
+    }
+
+    size = (size + (offset & cluster_mask) + cluster_mask) & ~cluster_mask;
+    offset &= ~cluster_mask;
+
+    if ((chk & QCOW2_OL_ACTIVE_L1) && s->l1_size) {
+        if (overlaps_with(s->l1_table_offset, s->l1_size * sizeof(uint64_t))) {
+            return QCOW2_OL_ACTIVE_L1;
+        }
+    }
+
+    if ((chk & QCOW2_OL_REFCOUNT_TABLE) && s->refcount_table_size) {
+        if (overlaps_with(s->refcount_table_offset,
+            s->refcount_table_size * sizeof(uint64_t))) {
+            return QCOW2_OL_REFCOUNT_TABLE;
+        }
+    }
+
+    if ((chk & QCOW2_OL_SNAPSHOT_TABLE) && s->snapshots_size) {
+        if (overlaps_with(s->snapshots_offset, s->snapshots_size)) {
+            return QCOW2_OL_SNAPSHOT_TABLE;
+        }
+    }
+
+    if ((chk & QCOW2_OL_INACTIVE_L1) && s->snapshots) {
+        for (i = 0; i < s->nb_snapshots; i++) {
+            if (s->snapshots[i].l1_size &&
+                overlaps_with(s->snapshots[i].l1_table_offset,
+                s->snapshots[i].l1_size * sizeof(uint64_t))) {
+                return QCOW2_OL_INACTIVE_L1;
+            }
+        }
+    }
+
+    if ((chk & QCOW2_OL_ACTIVE_L2) && s->l1_table) {
+        for (i = 0; i < s->l1_size; i++) {
+            if ((s->l1_table[i] & L1E_OFFSET_MASK) &&
+                overlaps_with(s->l1_table[i] & L1E_OFFSET_MASK,
+                s->cluster_size)) {
+                return QCOW2_OL_ACTIVE_L2;
+            }
+        }
+    }
+
+    if ((chk & QCOW2_OL_REFCOUNT_BLOCK) && s->refcount_table) {
+        for (i = 0; i < s->refcount_table_size; i++) {
+            if ((s->refcount_table[i] & REFT_OFFSET_MASK) &&
+                overlaps_with(s->refcount_table[i] & REFT_OFFSET_MASK,
+                s->cluster_size)) {
+                return QCOW2_OL_REFCOUNT_BLOCK;
+            }
+        }
+    }
+
+    if ((chk & QCOW2_OL_INACTIVE_L2) && s->snapshots) {
+        for (i = 0; i < s->nb_snapshots; i++) {
+            uint64_t l1_ofs = s->snapshots[i].l1_table_offset;
+            uint32_t l1_sz  = s->snapshots[i].l1_size;
+            uint64_t *l1 = g_malloc(l1_sz * sizeof(uint64_t));
+            int ret;
+
+            ret = bdrv_read(bs->file, l1_ofs / BDRV_SECTOR_SIZE, (uint8_t *)l1,
+                            l1_sz * sizeof(uint64_t) / BDRV_SECTOR_SIZE);
+
+            if (ret < 0) {
+                g_free(l1);
+                return ret;
+            }
+
+            for (j = 0; j < l1_sz; j++) {
+                if ((l1[j] & L1E_OFFSET_MASK) &&
+                    overlaps_with(l1[j] & L1E_OFFSET_MASK, s->cluster_size)) {
+                    g_free(l1);
+                    return QCOW2_OL_INACTIVE_L2;
+                }
+            }
+
+            g_free(l1);
+        }
+    }
+
+    return 0;
+}
+
+/*
+ * First performs a check for metadata overlaps (through
+ * qcow2_check_metadata_overlap); if that fails with a negative value (error
+ * while performing a check), that value is returned. If an impending overlap
+ * is detected, the BDS will be made unusable, the qcow2 file marked corrupt
+ * and -EIO returned.
+ *
+ * Returns 0 if there were neither overlaps nor errors while checking for
+ * overlaps; or a negative value (-errno) on error.
+ */
+int qcow2_pre_write_overlap_check(BlockDriverState *bs, int chk, int64_t offset,
+                                  int64_t size)
+{
+    int ret = qcow2_check_metadata_overlap(bs, chk, offset, size);
+
+    if (ret < 0) {
+        return ret;
+    } else if (ret > 0) {
+        fprintf(stderr, "qcow2: Preventing invalid write on metadata; "
+                "image marked as corrupt.\n");
+        bdrv_emit_qmp_error_event(bs, QEVENT_BLOCK_IMAGE_CORRUPTED,
+                BDRV_ACTION_REPORT, false);
+        qcow2_mark_corrupt(bs);
+        bs->drv = NULL; /* make BDS unusable */
+        return -EIO;
+    }
+
+    return 0;
+}
diff --git a/block/qcow2.h b/block/qcow2.h
index 4297487..fa2425b 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -289,6 +289,29 @@ enum {
     QCOW2_CLUSTER_ZERO
 };
 
+typedef enum QCow2MetadataOverlap {
+    QCOW2_OL_NONE           = 0,
+    QCOW2_OL_MAIN_HEADER    = (1 << 0),
+    QCOW2_OL_ACTIVE_L1      = (1 << 1),
+    QCOW2_OL_ACTIVE_L2      = (1 << 2),
+    QCOW2_OL_REFCOUNT_TABLE = (1 << 3),
+    QCOW2_OL_REFCOUNT_BLOCK = (1 << 4),
+    QCOW2_OL_SNAPSHOT_TABLE = (1 << 5),
+    QCOW2_OL_INACTIVE_L1    = (1 << 6),
+    /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
+     * reads. */
+    QCOW2_OL_INACTIVE_L2    = (1 << 7),
+} QCow2MetadataOverlap;
+
+/* Perform all overlap checks which don't require disk access */
+#define QCOW2_OL_CACHED \
+    (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_ACTIVE_L2 | \
+     QCOW2_OL_REFCOUNT_TABLE | QCOW2_OL_REFCOUNT_BLOCK | \
+     QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_INACTIVE_L1)
+
+/* The default checks to perform */
+#define QCOW2_OL_DEFAULT QCOW2_OL_CACHED
+
 #define L1E_OFFSET_MASK 0x00ffffffffffff00ULL
 #define L2E_OFFSET_MASK 0x00ffffffffffff00ULL
 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
@@ -390,6 +413,11 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 
 void qcow2_process_discards(BlockDriverState *bs, int ret);
 
+int qcow2_check_metadata_overlap(BlockDriverState *bs, int chk, int64_t offset,
+                                 int64_t size);
+int qcow2_pre_write_overlap_check(BlockDriverState *bs, int chk, int64_t offset,
+                                  int64_t size);
+
 /* qcow2-cluster.c functions */
 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
                         bool exact_size);
diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h
index 1942cc4..10fa0e3 100644
--- a/include/monitor/monitor.h
+++ b/include/monitor/monitor.h
@@ -48,6 +48,7 @@ typedef enum MonitorEvent {
     QEVENT_BALLOON_CHANGE,
     QEVENT_SPICE_MIGRATE_COMPLETED,
     QEVENT_GUEST_PANICKED,
+    QEVENT_BLOCK_IMAGE_CORRUPTED,
 
     /* Add to 'monitor_event_names' array in monitor.c when
      * defining new events here */
diff --git a/monitor.c b/monitor.c
index ee9744c..2c542e1 100644
--- a/monitor.c
+++ b/monitor.c
@@ -504,6 +504,7 @@ static const char *monitor_event_names[] = {
     [QEVENT_BALLOON_CHANGE] = "BALLOON_CHANGE",
     [QEVENT_SPICE_MIGRATE_COMPLETED] = "SPICE_MIGRATE_COMPLETED",
     [QEVENT_GUEST_PANICKED] = "GUEST_PANICKED",
+    [QEVENT_BLOCK_IMAGE_CORRUPTED] = "BLOCK_IMAGE_CORRUPTED",
 };
 QEMU_BUILD_BUG_ON(ARRAY_SIZE(monitor_event_names) != QEVENT_MAX)
 
